Mali 01: Pilot Study of CD4+ T Cell Immune Responses to Mycobacterium Tuberculosis. The protocol was closed to new enrollment on December 31st 2008. Completion of follow up visits remains. The last patient completed the study in December 2009. Data from the study have been presented at international meetings and manuscripts are in preparation. Mali 02: Establishment of Normal Parameters for Blood and Sputum with Samples Obtained From Volunteers in Bamako Ongoing Mali 03: Correlation of the Precursor Frequency of CD4 + Effector Memory T cells with Induration measured in the Tuberculin Skin Test (TST) Enrolling. The goal is to complete this protocol in 2011. Mali 04: A Cohort Observational Study to Assess the Virologic Response to Standard HIV Treatment in Bamako, Mali Commenced December 2008. Enrolling. Completion of enrollment in December 2009. Ongoing follow-up until December 2010. Mali 05: Strategic Timing of Antiretroviral Therapy (START) Multi-centered, international protocol commenced enrollment in Mali in October 2009 to evaluate the question of the most appropriate time to initiate antiretroviral therapy in persons with HIV infection. The Mali site has been a top enrolling site. Interim data has been presented in abstracts;manuscripts are in preparation.